By Jamie Stark, Sr Product Manager, Lync

In just one week, the worldwide Lync Community will be gathering in Las Vegas for Lync Conference 2014. One of the big topics we’ll be talking about at the conference is software-defined networking (SDN). We have seven core sessions talking about our strategy, the product enhancements we’ve made over the last year, and the partners who are working closely with us to bring SDN-powered solutions to market – Aruba Networks, HP, and Nectar. This is the second in our SDN blog series. If you missed my earlier blog that introduces what we’re up to with SDN, check it here.

Ensuring the reliable delivery of Lync traffic and a great user experience – especially as more users migrate to Lync mobile clients running on tablets and smartphones – mandates robust, properly installed Wi-Fi infrastructure, enforcement of QoS prioritization, and diagnostics that can quickly identify the root cause of performance issues. The former can be achieved by properly surveying the network infrastructure and ensuring it’s up to Lync standards, but the latter two items are harder to achieve. Why? Because there are often different teams managing network infrastructure and unified communications, each with its own services and tools. The good news is that SDN brings these two worlds together.

With the introduction of the Lync SDN API, the Lync Server can now interact directly with network infrastructure so QoS and services can be dynamically adjusted to always deliver the best possible experience. The Lync Server and clients can inform the network about an impending call, ongoing state changes, latency, jitter, packet loss, and other quality metrics. These metrics also inform the network’s diagnostics system about call issues, which can be visualized in real-time and archived for reporting purposes.

Microsoft has partnered with Aruba to bring the benefits of the Lync SDN API to life by integrating it with Aruba’s Wi-Fi controllers. Aruba was the first Wi-Fi infrastructure to qualify under the Lync Wi-Fi AP Qualification program, and is today the only Wi-Fi solution that identifies and differentiate encrypted Lync traffic types.

Now, through the Lync SDN API, Aruba obtains call set-up information, caller and callee data, and SIP URIs, ports, media type, and protocols in use. These data are used to ensure that Lync traffic streams receive the appropriate priority and level of service. QoS extends far beyond WMM and includes:

  • Identification and prioritization of Lync traffic based on individual voice, video, and desktop sharing traffic streams.

  • Traffic retagging ensures that over-the-air Lync traffic receives the right priority level even if the wired network infrastructure misprioritized or mistagged the traffic.

  • Lync-aware RF management ensures that jitter and packet loss are not introduced by the Wi-Fi infrastructure.

  • Lync-aware roaming takes Lync call status into account when enforcing client roaming for sticky clients, part of a patented technology called Client Match.

The result is that Lync users experience the highest quality voice and video on mobile devices, even in the face of network congestion.

Aruba Wi-Fi controllers leverage the Lync SDN API to proactively identify, troubleshoot, and prevent issues that could affect Lync quality. Post-call performance metrics include round-trip jitter, delay, packet loss, and Mean Opinion Scores (MOS) as seen by the Lync client. Lync status is presented on easy-to-use dashboards backed by centralized auditing and reporting, including reports on all Lync Wi-Fi calls and a mapping of client Wi-Fi connectivity health to Lync Call Quality. If a problem arises, the client-to-core visibility makes quick work of pinpointing and remediating the root cause.

Network data are pulled directly from the devices handling the Lync traffic – Aruba Wi-Fi access points, switches, remote VPN access points, and controllers – with no probes required. Removing the need for probes simplifies deployment, yields more consistently accurate results, ensures that data are correctly collected following network adds/moves/changes, and allows retrofits to existing deployments with minimal disruption or expense.


Lync SDN API integration is available for all Aruba Wi-Fi controllers and campus access points running Aruba OS 6.3 and higher. Please visit Aruba at http://www.arubanetworks.com/solutions/lync/ or send an e-mail to lyncready@arubanetworks.com for more details on enabling Lync mobility over Wi-Fi.

So once again, be sure to check out all the SDN sessions we have at this year’s Lync Conference!

Session Code Title Speakers Time & Location
NETW300 SDN: An Overview for UC Jamie Stark; Pascal  Menzes; Jim Burton Tue 11:00a in Pinyon 2
NETW301 SDN: Lync and Network Diagnostics Michael  Butler; Tom Tuttle

Tue 2:00p in Copperleaf 6

Wed 2:45p in Copperleaf 5
NETW302 SDN: Quality of Service Redefined Pascal  Menzes; Manfred Arndt

Tue 3:45p in Copperleaf 6

Wed 4:30p in Copperleaf 6
NETW303 SDN: Wi-Fi and Lync Thenu  Kittappa; Korneel Bullens

Wed 8:30a in Copperleaf 6

Wed 4:30p in Copperleaf 5

Aruba Networks is a Gold Sponsor (Booth #515 in the Expo Hall) as well participating in breakout sessions both with us on SDN, in the Solutions track, and in the Partner theatre as well.   

There’s a ton to learn – we can’t wait to start!

See you in Vegas!

Jamie Stark
@nomorephones